Emile-Joseph Yaacoub

Saccharide polymers, 3. Synthesis and polymerization of a 5,6-unsaturated fructofuranoid derivative

A new exo-fructofuranoid monomer 5 was synthesized through a four-step reaction. This unsaturated sugar monomer has been successfully tested in radical polymerization. Homo- and copolymerizations were carried out in solution under various conditions. The corresponding saccharide polymers were isolated as white powder and well characterized. Polymer compositions were determined by elemental analysis (C, H, N) and 1H and 13C NMR. Polymerization parameters were determined for the binary system 1,2,3,4-tetra-O-benzoyl-6-deoxy-α-D-threo-5-eno-hexofuranose-2-uloside (5)/MA giving the reactivity ratios r1 = 0.47 for 5 and r2 = 1.13 for MA. The thermal behaviour of saccharide polymers was investigated showing a linear relationship between the glass transition temperature (Tg) of the saccharide polymers and the sugar content. The saccharide polymers also showed optical activity and exhibit negative optical rotation. Both Tg and the specific optical rotations ([α]20D) increase with increasing sugar content.

Saccharide polymers, 4. Synthesis and polymerisation of 1,2-unsaturated fructopyranoid derivatives

Unsaturated fructopyranose derivatives like 2,6-anhydro-3,4,5-tri-O-benzoyl-1-desoxy-β-D-arabino- hex-1-enopyranose (3) and 2,6-anhydro-3,4,5-tri-O-acetyl-1-desoxy-β-D-arabino-hex-1-enopyranose (6), briefly called “Bz-exo-fructal” (3) and “Ac-exo-fructal” (6), were synthesised. These sugar monomers, which are exo-cyclic vinyl ethers, were investigated in polymerisation reactions. The corresponding “saccharide polymers”, homo- and copolymers, were synthesised under free radical conditions. The structure and composition of the “saccharide polymers” were determined by elemental analysis, 1H and 13C NMR, and FT-IR spectroscopy. Characterisation and properties of the various polymers in terms of molecular weight, optical rotation, and glass transition temperature are reported.

Sugar latexes as a new type of binder for water‐based paint and coating

Sugar latexes based on saccharid derivatives, such as 3-MDG, 1- or 3-MDF and ITDF, have been synthesized in batch and semi-continuous emulsion polymerization. The polymerizations were carried out at 60 or 70°C, initiated by potassium peroxodisulfate, (KPS), in the presence of either ionic or non-ionic surfactant. The effect of the type and concentration of the surfactant and the type of polymerization process on the colloidal and rheological properties was studied. It was found that the particles size increased with using a non-ionic surfactant. Monodisperse particles were obtained by using SDS below its CMC, and smaller polydisperse latexes were observed when the SDS conc. was above the CMC. The latexes exhibit different non-Newtonian flows depending on the solid content and on the additives.